diff --git a/docs/i-tutorials/unit-1.7-helmholtz/pml.ipynb b/docs/i-tutorials/unit-1.7-helmholtz/pml.ipynb
index b05de4288..1ff23a3c3 100644
--- a/docs/i-tutorials/unit-1.7-helmholtz/pml.ipynb
+++ b/docs/i-tutorials/unit-1.7-helmholtz/pml.ipynb
@@ -253,8 +253,8 @@
     "\n",
     "with TaskManager():\n",
     "    lam = ArnoldiSolver(a.mat, m.mat, fes.FreeDofs(), \n",
-    "                        u.vecs, shift=400)\n",
-    "Draw(u)"
+    "                        list(u.vecs), shift=400)\n",
+    "Draw(u);"
    ]
   },
   {
@@ -292,7 +292,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3",
+   "display_name": "Python 3 (ipykernel)",
    "language": "python",
    "name": "python3"
   },
@@ -306,7 +306,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.8.5"
+   "version": "3.11.1"
   }
  },
  "nbformat": 4,